Method for removing meat from bone fragments

Abstract

Apparatus for removing and recovering meat from trimmed and untrimmed bone fragments comprises a hollow sleeve open at one end for receiving a quantity of bone fragments to be processed. Hydraulic cylinders raise the sleeve to bring one end into engagement with an extrusion block, and a piston slidably disposed at the other end of the sleeve is advanced initially by relatively high speed jack cylinders and finally by a low speed ram cylinder to compress the bone fragements against the block. The extrusion block includes a plurality of concentric annular recesses and interfitting extrusion rings which form an inwardly facing foraminous surface through which meat recovered in fluid form as a result of the compression process passes. The rings are slidably received within the recesses to facilitate removal for cleaning, and are partially extended from the recesses by a pneumatic cylinder after each compression cycle to dislodge bone residue from the foraminous surface. A pressure and seal is maintained between the sleeve and the piston and extrusion head by the combination of an O-ring fitted into an outer circumferential channel on the piston and an inner circumferential channel communicating with an outflow line which relieves pressure from the O-ring.

I claim: 
     
       1. A method for removing and recovering meat from a mass of bone fragments comprising the steps of: compressing said mass in means providing a chamber to form a press cake of substantially reduced volume;   collecting the meat which extrudes from the mass during said compression through an extrusion head having an extrusion block including at least one recess for passing extruded meat from said chamber, and at least one extrusion member interspaced therein; and extendable from and retractable in said recess, said extrusion block and said extrusion member together forming a foraminous surface in said chamber;   extending each said extrusion member from said recess to release residual solid matter retained within the foramina of said foraminous surface; and   removing said press cake from said chamber.   
     
     
       2. A method for removing and recovering meat from bone fragments as defined in claim 1 wherein said extrusion member is when required at least partially removed from said recess for cleaning following removal of said press cake. 
     
     
       3. A method for removing and recovering meat as defined in claim 1 wherein said extrusion member is positioned within said recess by means of push rods, and extended from said recess following compression of said mass by actuating said push rods. 
     
     
       4. A method for removing and recovering meat as defined in claim 2 wherein said extrusion head includes a plurality of said recesses each having an extrusion member interspaced therein, and wherein said extrusion members are simultaneously extended to remove residual solid matter from said foraminous. 
     
     
       5. A method of removing and recovering meat from bone fragments comprising the steps of: compacting a mass of bone fragments into a dense press cake against a rigid foraminous wall while meat removed from said bone fragments during compaction extrudes through the foramina in said wall;   temporarily enlarging the foramina in said wall after a dense press cake of bone fragments has been formed thereon; and   removing said press cake from said wall along with residual solid matter retained in said foramina.